The present invention relates to telephony communication in general, and to methods and systems for establishing and controlling telephone calls, in particular.
Reference is now made to FIG. 1, which is a schematic illustration of a system for placing a call between a pre-paid mobile subscriber, and a land subscriber, which is known in the art. The system is includes a mobile switching center (MSC) 4, a central office (CO) 10 and a pre-paid system (PPS) 14. Pre-paid system 14 is also know as adjunct switch or service node. Mobile switching center (MSC) 4 is a gateway for a plurality of mobile subscribers (such as mobile subscriber 2) to a wide area telephony network. Central office (CO) 10 is a gateway for a plurality of land subscribers (such as land subscriber 8) to that wide area telephony network. Pre-paid system (PPS) 14 is operative to authorize and control telephony calls from mobile subscriber 2 to another subscriber such as a land subscriber 8 or other mobile subscribers. Mobile switching center (MSC) 4 is coupled to central office (CO) 10 and to pre-paid system (PPS) 14 via respective signaling links 36 and 34. It is noted that signaling links 34 and 36 are typically routed between the various network nodes by signal transfer point (STP) units (not shown), which serve as routers.
In the terminology of conventional telephony, a voice link between network nodes such as links 16, 22 and 28, represents a time slot in a multiplexed voice trunk. Each of the time slots is identified by a circuit identification code (CIC).
When mobile subscriber 2 initiates a telephone call to land subscriber 8, he first establishes a link 6 to MSC 4. It is noted that the type of link between a terminal and a respective network node, is typically different than a link between two network nodes.
MSC 4 initiates a call to PPS 14 via signaling link 34 and further directs the call thereto, via voice link 16, between ports 18 and 20. PPS 14 authorizes that call according to the account status of the mobile subscriber 2 and initiates a call back to MSC 4 via signaling link 34 and further directs that call thereto via voice link 22, between ports 24 and 26. MSC initiates a call to central office (CO) 10 via signaling link 36 and further directs the call received at port 26 to central office (CO) 10, via link 28, between ports 30 and 32. Central office (CO) 10 further directs the call to land subscriber 8 via a link 12.
PPS 14 constantly monitors the call established between mobile subscriber 2 and land subscriber 8, as it passes there through. It is noted that establishing such a telephone call requires allocating three ports in the MSC 4, two ports in the PPS 14 and one port in the CO 10. Each voice connection port 18, 26 and 30 employs a different circuit identification code and hence, MSC 4 has to assign three CICs for establishing that telephone call.
It will be appreciated by those skilled in the art that for the purpose of establishing a pre-paid call, MSC 4 has to initiate two calls, one from port 18 and another from port 30. The initiation and management of these calls, significantly load the processors of MSC 4. In addition, the capacity of MSC 4 is limited to a predetermined number of calls, which can be managed and switched thereby. Hence, every such pre-paid call, requires switch resources which could have been used for two regular calls. This significantly increases the cost of such a pre-paid call in terms of switching resource allocation.
Reference is now made to FIG. 2, which is a schematic illustration of a system for placing a call between a pre-paid mobile subscriber, and a land subscriber, which is known in the art. MSC 44, CO 50, and PPS 54 are analogous to MSC 4 (FIG. 1), CO 10, and PPS 14, respectively. MSC 44 is coupled to CO 50 and to PPS 54 via respective signaling links 40 and 56.
When mobile subscriber 42 initiates a telephone call to land subscriber 48, he first establishes a link 46 to MSC 44. MSC 44 initiates a call to PPS 54 via signaling link 56. PPS 54 authorizes that call according to the account status of the mobile subscriber 42 and initiates a return call, back to MSC 44 via signaling link 56. In that return call, PPS 54 directs MSC 44, to connect ports 60 and 62 via a voice link 64. The establishing of voice link 64 is known in the art as xe2x80x9cloop-aroundxe2x80x9d.
In turn, MSC 44 initiates a call to CO 50 via signaling link 40. MSC 44, further directs the call, received at port 62, to CO 50, via voice link 58, between ports 66 and 68. CO 50 further directs the call to land subscriber 48.
PPS 54 constantly monitors the call established between mobile subscriber 42 and land subscriber 48, by communicating at a signaling level with MSC 44. It is noted that establishing such a telephone call requires allocating three ports in MSC 44, and a single port in CO 50.
Each voice connection port 60, 62 and 66 employs a different circuit identification code and hence, MSC 44 has to assign three CICs for establishing that telephone call. It will be appreciated by those skilled in the art that for the purpose of establishing that pre-paid call, MSC 44 has to initiate two calls, one from port 60 and another from port 66, which significantly load the processors thereof.
U.S. Pat. No. 5,708,702 to De Paul et al. entitled xe2x80x9cDynamic STP routing in response to triggeringxe2x80x9d is directed to a method for submitting queries to a remote database using SCCP/TCAP protocols. The method employs a common channel interoffice signaling (CCIS) network to determine a parameter respective of the called party (e.g., if the called party is busy), prior to construction of a telephone connection. When an originating end office receives a request to connect a caller to a called party, the originating end office sends a message to the terminating end office, via the CCIS network. The terminating end office determines if the called party is busy. If the called party is busy, then the terminating end office informs the originating end office by sending a message via the CCIS network, and the originating end office provides a busy signal to the caller. If the called party is not busy, then the terminating end office informs the originating end office, and a telephone connection is constructed between the caller and the called party.
U.S. Pat. No. 5,920,562, to Christie et al. entitled xe2x80x9cSystems and methods for providing enhanced services for telecommunication callxe2x80x9d is directed to a method for providing enhanced services for calls over Asynchronous Transfer Mode (ATM) system. Such services include voice messaging, facsimile messaging, mail boxes, voice recognition, conference bridging, calling card, menu routing, prepay card, tone detection and call forwarding. The system includes a service platform system, which interacts with a plurality of communication terminals. The service platform system includes a signaling processor, a service platform and an interworking unit.
The signaling processor receives signaling messages in ATM format from a source terminal, processes them and determines which services the call requires and which operations have to be performed. The signaling processor then sends a signal to the service platform, designating the application to use in order to process the call. The interworking unit receives signals from the source terminal and from the signaling processor, and converts the ATM cells, which it has received from the source terminal, to a form, which is compatible with the service platform. The service platform processes the signal received from interworking unit according to the selected application, and sends the processing results to the signaling processor, and the processed call to the interworking unit. The interworking unit sends the processed call either to the source terminal or to another service platform. The signaling processor sends the processed call either to the target terminal, to the source terminal or to another service platform, according to the control messages included in the processing results.
It is an object of the present invention to provide a novel method and system for management of telephony nodes, which overcomes the disadvantages of the prior art. In accordance with the present invention, there is thus provided a network architecture for establishing telephony connection. The network architecture includes a call management node, a first network node and a second network node. The first network node is coupled to the call management node via a first signaling link, and further coupled to at least one first node telephony subscriber. The second network node is coupled to the call management node via a second signaling link, to the first network node via at least one voice link, and further coupled to at least one second node telephony subscriber.
In accordance with another aspect of the present invention, there is thus provided a method for managing a telephony network. The method includes the steps of determining the destination node identification and the destination node communication link parameters of a destination node and establishing signaling communication between the call management node and the destination node.
The destination node identification and the destination node communication link parameters are determined according to origin node identification and origin node communication link parameters of an origin node. Signaling communication between the call management node and the destination node is established by using the destination node communication link parameters. The origin node communication link parameters and the destination node communication link parameters are directed to a unique communication link between the origin node and the destination node.
In accordance with a further aspect of the present invention, there is thus provided a method for managing a telephony network. The method includes the steps of extracting the destination node identification and destination node communication link parameters of the destination node and establishing signaling communication between the call management node and the destination node.
The destination node identification and destination node communication link parameters are extracted from at least one field in a signaling message received from the origin node. The signaling communication between the call management node and the destination node is established by using the destination node communication link parameters. The origin node determines the origin node communication link parameters. The origin node communication link parameters and the destination node communication link parameters are directed to a unique communication link between the origin node and the destination node.
In accordance with another aspect of the present invention, there is thus provided a call management system. The call management system includes a processor, a storage unit and a signaling interface, wherein the storage unit is coupled to the processor. The storage unit contains a translation table associating the network resources of the first network node with the network resources of second network node. The signaling interface establishes signaling communication to the first network node and to the second network node, wherein the first network node is further coupled to the second network node via a multi-channel connection.